[PATCH v3 00/19] Exynos SYSMMU (IOMMU) integration with DT and DMA-mapping subsystem

Joonyoung Shim
2015-01-07T09:55:31Z

Hi Javier,

On 01/07/2015 06:33 PM, Javier Martinez Canillas wrote:
> Hello Joonyoung,
>
> On 01/07/2015 03:03 AM, Joonyoung Shim wrote:
>> On 01/06/2015 06:49 PM, Javier Martinez Canillas wrote:
>>>
>>> Also I tried forcing the kernel to not disable unused power domains by
>>> passing the pd_ignore_unused parameter to the kernel command line. I
>>> see on the kernel log a "genpd: Not disabling unused power domains"
>>> message but HDMI output still has the stripes that Sjoerd mentioned.
>>> Do you know if Exynos DRM HDMI in mainline is supposed to work without
>>> SysMMU / IOMMU support?
>>>
>>
>> I don't think iommu support and power domain issue are related. I also
>> get displaying stripes via hdmi but it is just power domain issue
>> regardless iommu support.
>>
>> I observed 8th bit from 0x1445000C register of mixer is set to 1 with
>> displaying stripes. It means "The graphic layer0 line buffer underflow".
>> There was same underflow issue on Exynos4 based boards. As Marek said,
>> because LCD0 power domain was turned off.
>>
>
> Interesting, thanks a lot for sharing this information.
>
>> I just tried to turn off DISP1 power domain at u-boot and DISP1 power
>> domain is turned on from kernel hdmi and mixer driver on odroid xu3
>> board. As the result, i can see displaying penguin logo from hdmi.
>>
>
> Can you share the patches you are using to turn on the DISP1 power domain
> since AFAIU the kernel does not know about the DISP1 power domain after
> commit d51cad7df871 ("ARM: dts: remove display power domain for exynos5420").
>
> I tried reverting that commit before so the kernel knows about the DISP1
> power domain and booting with pd_ignore_unused but still had the stripes.
>

I add DISP1 power domain on dts and please refer below patch[0] with
some modification on hdmi phy(Actually, i think this is not related).
You also should disable DISP1 power domain from bootloader.

>> But the problem exists still because it is failed to control on/off of
>> DISP1 power domain more than twice from kernel hdmi and mixer driver.[0]
>>
>
> Something that is not clear to me is how display panel is working on the
> Peach boards if this is a power domain issue since according to the manual
> both the modules used for display (LCD controller and DP) and the modules
> used for HDMI (MIXER and HDMI) belong to the same power domain (DISP1).
>

I don't know about that because i just tested on odroid xu3 board
without display panel. Hmm, It can be any conditions to success on/off
power domain e.g. power state of clocks and of on/off order display
devices.

Is DISP1 power domain disabled on Peach boards to save power, not always
on?

> Or am I misunderstanding something?
>
> Thanks a lot for your help and best regards,
> Javier
>

Thanks.

[0]:
---
arch/arm/boot/dts/exynos5420.dtsi | 10 ++++++++++
drivers/clk/samsung/clk-exynos5420.c | 4 ++--
drivers/gpu/drm/exynos/exynos_hdmi.c | 8 ++------
include/dt-bindings/clock/exynos5420.h | 2 ++
4 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
index 8617a03..ff9ad4a 100644
--- a/arch/arm/boot/dts/exynos5420.dtsi
+++ b/arch/arm/boot/dts/exynos5420.dtsi
@@ -270,6 +270,14 @@
reg = <0x10044120 0x20>;
};

+ disp1_pd: power-domain at 100440C0 {
+ compatible = "samsung,exynos4210-pd";
+ reg = <0x100440C0 0x20>;
+ clocks = <&clock CLK_FIN_PLL>, <&clock CLK_MOUT_SW_ACLK200>,
+ <&clock CLK_MOUT_USER_ACLK200_DISP1>;
+ clock-names = "oscclk", "pclk0", "clk0";
+ };
+
pinctrl_0: pinctrl at 13400000 {
compatible = "samsung,exynos5420-pinctrl";
reg = <0x13400000 0x1000>;
@@ -704,6 +712,7 @@
"sclk_hdmiphy", "mout_hdmi";
phy = <&hdmiphy>;
samsung,syscon-phandle = <&pmu_system_controller>;
+ samsung,power-domain = <&disp1_pd>;
status = "disabled";
};

@@ -717,6 +726,7 @@
interrupts = <0 94 0>;
clocks = <&clock CLK_MIXER>, <&clock CLK_SCLK_HDMI>;
clock-names = "mixer", "sclk_hdmi";
+ samsung,power-domain = <&disp1_pd>;
};

gsc_0: video-scaler at 13e00000 {
diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index 848d602..52ba0e6 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -635,7 +635,7 @@ static struct samsung_mux_clock exynos5x_mux_clks[] __initdata = {
SRC_TOP3, 0, 1),
MUX(0, "mout_user_aclk400_mscl", mout_user_aclk400_mscl_p,
SRC_TOP3, 4, 1),
- MUX(0, "mout_user_aclk200_disp1", mout_user_aclk200_disp1_p,
+ MUX(CLK_MOUT_USER_ACLK200_DISP1, "mout_user_aclk200_disp1", mout_user_aclk200_disp1_p,
SRC_TOP3, 8, 1),
MUX(0, "mout_user_aclk200_fsys2", mout_user_aclk200_fsys2_p,
SRC_TOP3, 12, 1),
@@ -693,7 +693,7 @@ static struct samsung_mux_clock exynos5x_mux_clks[] __initdata = {
SRC_TOP10, 0, 1),
MUX(0, "mout_sw_aclk400_mscl", mout_sw_aclk400_mscl_p,
SRC_TOP10, 4, 1),
- MUX(0, "mout_sw_aclk200", mout_sw_aclk200_p, SRC_TOP10, 8, 1),
+ MUX(CLK_MOUT_SW_ACLK200, "mout_sw_aclk200", mout_sw_aclk200_p, SRC_TOP10, 8, 1),
MUX(0, "mout_sw_aclk200_fsys2", mout_sw_aclk200_fsys2_p,
SRC_TOP10, 12, 1),
MUX(0, "mout_sw_aclk400_wcore", mout_sw_aclk400_wcore_p,
diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 563a19e..f3cdf80 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -1664,7 +1664,6 @@ static void hdmi_mode_apply(struct hdmi_context *hdata)

static void hdmiphy_conf_reset(struct hdmi_context *hdata)
{
- u8 buffer[2];
u32 reg;

clk_disable_unprepare(hdata->res.sclk_hdmi);
@@ -1672,11 +1671,8 @@ static void hdmiphy_conf_reset(struct hdmi_context *hdata)
clk_prepare_enable(hdata->res.sclk_hdmi);

/* operation mode */
- buffer[0] = 0x1f;
- buffer[1] = 0x00;
-
- if (hdata->hdmiphy_port)
- i2c_master_send(hdata->hdmiphy_port, buffer, 2);
+ hdmiphy_reg_writeb(hdata, HDMIPHY_MODE_SET_DONE,
+ HDMI_PHY_ENABLE_MODE_SET);

if (hdata->type == HDMI_TYPE13)
reg = HDMI_V13_PHY_RSTOUT;
diff --git a/include/dt-bindings/clock/exynos5420.h b/include/dt-bindings/clock/exynos5420.h
index 8dc0913..15b9bb2 100644
--- a/include/dt-bindings/clock/exynos5420.h
+++ b/include/dt-bindings/clock/exynos5420.h
@@ -204,6 +204,8 @@
#define CLK_MOUT_MAUDIO0 643
#define CLK_MOUT_USER_ACLK333 644
#define CLK_MOUT_SW_ACLK333 645
+#define CLK_MOUT_USER_ACLK200_DISP1 646
+#define CLK_MOUT_SW_ACLK200 647

/* divider clocks */
#define CLK_DOUT_PIXEL 768
--
1.9.1